Background— Although primary intraventricular hemorrhage is frequently due to trauma or vascular lesions, the etiology of idiopathic primary intraventricular hemorrhage (IP-IVH) is not defined.

Aims— Herein, we test the hypothesis that cerebral small vessel diseases (cSVD) including hypertensive cSVD (HTN-cSVD) and cerebral amyloid angiopathy (CAA) are associated with IP-IVH.

Methods— Brain magnetic resonance imaging (MRI) from consecutive patients (January 2011 to September 2019) with non-traumatic intracerebral hemorrhage (ICH) from a single referral center were reviewed for the presence of HTN-cSVD (defined by strictly deep or mixed-location ICH/cerebral microbleeds [CMBs]) and CAA (applying modified Boston criteria).

Results— 46 (4%) out of 1,276 patients were identified as having IP-IVH. Among these, the mean age was 74.4 ± 12.2 years and 18 (39%) were females. 40 (87%) had hypertension, and the mean initial blood pressure was 169.2 ± 40.4/88.8 ± 22.2 mmHg. Of the 35 (76%) patients who received a brain MRI, two (6%) fulfilled the modified Boston criteria for possible CAA and 10 (29%) for probable CAA. Probable CAA was found at a similar frequency when comparing IP-IVH patients to the remaining patients with primary intraparenchymal hemorrhage (P-IPH) (27%, p = 0.85). Furthermore, imaging evidence for HTN-cSVD was found in 8 (24%) patients with IP-IVH compared to 209 (28%, p = 0.52) patients with P-IPH.

Conclusions— Among IP-IVH patients, CAA was found in approximately one-third of patients, whereas HTN-cSVD was detected in 23%—both similar rates to P-IPH patients. Our results suggest that both cSVD subtypes may be associated with IP-IVH.

背景——虽然原发性脑室内出血通常是由外伤或血管损伤引起的，但特发性原发性脑室内出血 (IP-IVH) 的病因尚未明确。

目标——在此，我们检验了脑小血管疾病 (cSVD) 包括高血压 cSVD (HTN-cSVD) 和脑淀粉样血管病 (CAA) 与 IP-IVH 相关的假设。

方法 - 对来自单一转诊中心的连续患者（2011 年 1 月至 2019 年 9 月）的非创伤性脑出血 (ICH) 的脑磁共振成像 (MRI) 进行了 HTN-cSVD（严格定义为深部或混合位置 ICH/脑微出血 [CMB]）和 CAA（应用修改后的波士顿标准）。

结果——1,276 名患者中有 46 名 (4%) 被确定为患有 IP-IVH。其中，平均年龄为 74.4 ± 12.2 岁，18 人 (39%) 为女性。40 (87%) 患有高血压，平均初始血压为 169.2 ± 40.4/88.8 ± 22.2 mmHg。在接受脑部 MRI 的 35 名 (76%) 患者中，2 名 (6%) 符合可能 CAA 的修订波士顿标准，10 名 (29%) 符合可能 CAA 的标准。在将 IP-IVH 患者与其余原发性脑实质出血 (P-IPH) 患者进行比较时，发现可能的 CAA 的频率相似（27%，p = 0.85）。此外，在 8 名（24%）IP-IVH 患者中发现了 HTN-cSVD 的影像学证据，而在 P-IPH 患者中发现了 209 名（28%，p = 0.52）患者。

结论——在 IP-IVH 患者中，大约三分之一的患者发现 CAA，而在 23% 的患者中检测到 HTN-cSVD——两者的发生率与 P-IPH 患者相似。我们的结果表明，这两种 cSVD 亚型都可能与 IP-IVH 相关。